How many stoves can be hooked up to one chimney? For every 12 square inches of chimney opening, you can hook up one stove, For example, a 9 inch by 9 inch chimney opening (81 square inches) you can hook up seven box stoves. Never hook up two stoves to the same chimney at the same level.
How about fireplaces? Preferably only one per chimney. 7 inch by 7 inch is minimum size smoke outlet. It should never be smaller than the one half of the fireplace opening.